Azo dyestuffs

ABSTRACT

Polyester fibres are dyed in yellow and orange-red color shades with good fastness to light and wet processing when dyestuffs of the formula ##STR1## wherein K denotes the radical of a 5-amino-pyrazole coupling component which couples in the 4-position, 
     R denotes an optionally substituted alkyl, cycloalkyl, aralkyl or aryl radical and the ring A can contain further non-ionic substitutents customary in dyestuff chemistry, are used.

The invention relates to disperse dyestuffs of the formula ##STR2## wherein K denotes the radical of a 5-amino-pyrazole coupling component which couples in the 4-position,

R denotes an optionally substituted alkyl, cycloalkyl, aralkyl or aryl radical and the ring A can contain further non-ionic substituents customary in dyestuff chemistry.

Preferred dyestuffs correspond to the formula ##STR3## wherein R₁ represents alkyl or aryl,

R₂ represents hydrogen, halogen, CN, CF₃, NO₂, Q₁, --OQ₁, --COOQ₁, --CONQ₁ Q₂ or NHCOQ₁,

R₃ represents hydrogen, halogen, CF₃, Q₁ or OQ₁,

R₄ represents Q₂, aryl, cycloalkyl or a radical of a heterocyclic compound and

R₅ represents Q₁, --COOQ₂ or --CON(Q₂)₂,

wherein

Q₁ denotes alkyl or aryl and

Q₂ denotes hydrogen, alkyl or aralkyl.

The abovementioned alkyl, aralkyl, cycloalkyl and aryl radicals can contain further non-ionic substituents or the radical COOH.

Within the scope of this invention, suitable alkyl is, in particular, alkyl with 1 to 4 C atoms, which can be optionally further monosubstituted by cyano, halogen, such as chlorine, bromine or fluorine, hydroxyl or C₁ -C₄ -alkoxy, for example methyl, ethyl, n-propyl, iso-propyl, n-butyl, tert.-butyl, cyanoethyl or 2-chloroethyl.

Suitable aryl is, in particular, phenyl which is optionally monosubstituted to trisubstituted by halogen, C₁ -C₄ -alkyl, C₁ -C₄ -alkoxy, nitro, cyclohexyl or phenyl.

"Bulky" radicals are in those positions where they cause no steric hindrance, for example tert.-butyl is in the m-position or p-position of a phenyl radical.

Suitable halogen is chlorine, bromine or fluorine, but preferably chlorine.

Suitable heterocyclic radicals are the 2-thienyl radical and, above all, the 3-thiacyclopentyl radical.

Suitable aralkyl is, for example, benzyl or phenethyl.

Suitable cycloalkyl is, for example, cyclopentyl, cyclohexyl and cycloheptyl.

Particularly preferred dyestuffs are those of the formula ##STR4## wherein R₁ ' represents phenyl which is optionally monosubstituted to trisubstituted by C₁ -C₄ -alkyl, chlorine, nitro, cyclohexyl or phenyl,

R₂ ' stands halogen, cyano, trifluoromethyl, nitro, C₁ -C₄ -alkyl or C₁ -C₄ -alkoxy,

R_(3') stands H, halogen, trifluoromethyl, C₁ -C₄ -alkyl or C₁ -C₄ -alkoxy,

R₄ ' stands hydrogen, C₁ -C₄ -alkyl or phenyl and R₅ ' stands C₁ -C₄ -alkyl.

Very particularly preferred dyestuffs are those of the formula ##STR5## wherein R₁ " represents phenyl, tolyl or chlorophenyl,

R₂ " and R₃ " represent chlorine,

R₄ " represents phenyl and

R₅ " represents methyl.

The new dyestuffs are prepared in a manner which is in itself known by customary diazotisation reactions and coupling reactions.

The dyestuffs according to the invention are of very high tinctorial strength and are suitable for dyeing synthetic fibre materials, in particular polyamides, such as, for example, polycaprolactam, polyhexamethylenediamine adipate or polyaminoundecanoic acid, but very particularly polyesters, such as polyethylene terephthalate and poly-1,4-cyclohexanedimethylene terephthalate, from aqueous liquors or organic solvents. The types of fibre mentioned are dyed in deep yellow to orange-red shades with good fastness properties in use, such as, for example, fastness to light and wet processing.

EXAMPLE 1

35 g of 4-amino-2,5-dichloro-benzenesulphonic acid 3-chloro-phenyl ester are suspended in 400 ml of water and 30 ml of concentrated hydrochloric acid.

A 10% strength sodium nitrite solution is added dropwise at 0°-5° C. in the course of 15 minutes. After stirring the mixture for one hour at the temperature indicated, the excess nitrite is destroyed with amidosulphonic acid. This diazonium salt suspension is then added dropwise to a solution of 18 g of 1-phenyl-3-methyl-5-amino-pyrazole and 60 ml of concentrated hydrochloric acid at 0°-5° C. in the course of 30 minutes. After stirring the mixture for 1 hour, the pH value is adjusted to 5 by slowly adding 10% strength sodium hydroxide solution. As soon as coupling to give the dyestuff is complete, the precipitate is filtered off, washed and dried. About 40 g of a dyestuff of the formula ##STR6## are obtained.

DYEING EXAMPLES

(1) 1 part of the dyestuff obtained according to Example 1, finely dispersed by customary processes, is stirred into 2,000 parts of water. A pH value of 5 to 6 is established with acetic acid, and 4 parts of ammonium sulphate and 2 parts of a commercially available dispersing agent based on a condensation product of naphthalenesulphonic acid and formaldehyde are added. 100 parts of a polyester fabric based on polyethylene glycol terephthalate are introduced into the dye liquor thus obtained and dyeing is carried out at 120°-130° C. for 11/2 hours. After subsequent rinsing, reductive after-treatment with a 0.2% strength alkaline sodium dithionite solution at 60° C. for 15 minutes, rinsing and drying, a reddish-tinged yellow dyeing with good fastness properties, in particular good fastness to light and sublimation, is obtained.

(2) 100 parts of a fabric made of polyethylene terephthalate fibres are introduced, at room temperature, into a dyebath which is prepared from 1 part of the monoazo dyestuff of Example 1 and 1,000 parts of tetrachloroethylene. The bath is heated to 110° C. in the course of 20 minutes, whilst vigorously circulating the liquor, and is kept at this temperature for 45 minutes. The liquor is then separated off and the fabric is rinsed with fresh tetrachloroethylene at 40° C. After separating off the rinsing liquor, the dyed material is freed from adhering solvent by spinning and drying in a stream of air. A strong reddish-tinged yellow dyeing with good general fastness properties is obtained.

(3) 0.1 g of the well-dispersed dyestuff according to Example 1 is introduced, at 40° C. into 1 l of water, which also contains 0.2 g of sodium dinaphthylmethanesulphonate and 0.3 g of cresotic acid methyl ester. 10 g of a fabric made of polyethylene terephthalate are introduced into this bath, the temperature of the dyebath is increased to 100° C. in the course of about 20 minutes and dyeing is carried out at this temperature for 60-90 minutes. A strong reddish-tinged yellow dyeing with good fastness to sublimation and light is obtained.

Similar dyestuffs which have similar properties to that obtained according to Example 1 are formed when the following diazo components containing sulphonic acid ester groups are diazotised and the diazotisation products are coupled to the following 5-amino-pyrazole coupling components. The dyestuffs dye synthetic fibre materials, such as polyesters and polyamides, in the colour shades indicated, with good fastness properties, for example good fastness to light, wet processing and sublimation.

    __________________________________________________________________________     Ex-                                              Colour                        ample                                                                              Diazo component        Coupling component    shade                         __________________________________________________________________________     2   4-amino-2,5-dichloro-benzenesulphonic                                                                 1-phenyl-3-methyl-5-amino-pyrazole                                                                   yellow                            acid 3-methyl-phenyl ester                                                 3   4-amino-2,5-dichloro-benzenesulphonic                                                                 1-ethyl-3-methyl-5-amino-pyrazole                                                                    yellow                            acid 4-methyl-phenyl ester                                                 4   4-amino-2,5-dichloro-benzenesulphonic                                                                 3-methyl-5-amino-pyrazole                                                                            yellow                            acid 2-chloro-phenyl ester                                                 5   4-amino-2,5-dichloro-benzenesulphonic                                                                 1-(2-chloro-phenyl)-3-methyl-5-amino-                                                                yellow                            acid 4-chloro-phenyl ester                                                                            pyrazole                                            6   4-amino-2,5-dichloro-benzenesulphonic                                                                 1-cyclohexyl-3-methyl-5-amino-pyrazole                                                               yellow                            acid 2,4-dichloro-phenyl ester                                             7   4-amino-2,5-dichloro-benzenesulphonic                                                                 1-benzyl-3-methyl-5-amino-pyrazole                                                                   yellow                            acid 2-ethyl-phenyl ester                                                  8   4-amino-2,5-dichloro-benzenesulphonic                                                                 1-(2-phenethyl)-3-methyl-5-amino-pyrazole                                                            yellow                            acid 3,5-dimethyl-phenyl ester                                             9   4-amino-2,5-dichloro-benzenesulphonic                                                                 1-[4-(N,N-bis-(2-hydroxyethyl)-sulph-                                                                yellow                            acid 4-nitro-phenyl ester                                                                             amoyl)-naphth-1-yl]-3-methyl-5-amino-                                          pyrazole                                            10  4-amino-3-chloro-benzenesulphonic acid                                                                1-ethyl-3-carboxybutyl-5-amino-pyrazole                                                              yellow                            2,4,5-trichloro-phenyl ester                                               11  4-amino-3-nitro-benzenesulphonic acid                                                                 1-phenyl-3-(N-ethyl-carbamoyl)-5-amino-                                                              yellow                            4-chloro-2-methyl-phenyl ester                                                                        pyrazole                                            12  4-amino-2-chloro-5-cyano-benzenesulph-                                                                1-(3-hydroxypropyl)-3-methyl-5-amino-                                                                yellow                            onic acid 2-ethyl-phenyl ester                                                                        pyrazole                                            13  4-amino-2,5-dimethyl-benzenesulfonic                                                                  1-(1,2,2-trimethyl-2-hydroxy-ethyl)-3-                                                               yellow                            acid 2,3-dimethyl-phenyl ester                                                                        methyl-5-amino-pyrazole                             14  4-amino-3-chloro-6-methoxy-benzene-                                                                   1-phenyl-3-methyl-5-amino-pyrazole                                                                   yellow                            sulphonic acid 2,4-dimethyl-phenyl                                             ester                                                                      15  4-amino-2-methoxy-5-nitro-benzenesulph-                                                               1-benzyl-3-methyl-5-amino-pyrazole                                                                   yellow                            onic acid 4-chloro-2,5-dimethyl-phenyl                                         ester                                                                      16  4-amino-3-ethoxy-benzenesulphonic acid                                                                1-phenyl-3-(N,N-dimethyl-carbamoyl)-5-                                                               yellow                            2,5-dimethyl-phenyl ester                                                                             amino-pyrazole                                      17  4-amino-2,5-di-trifluoromethyl-benzene-                                                               1-(2,5-dichloro-phenyl)-3-methyl-5-                                                                  yellow                            sulphonic acid 2-isopropyl phenyl ester                                                               amino-pyrazole                                      18  4-amino-3-trifluoromethyl-benzenesulph-                                                               1-m-tolyl-3-methyl-5-amino-pyrazole                                                                  yellow                            onic acid 4-tert.-butyl-phenyl ester                                       19  4-amino-2,5-dichloro-benzenesulphonic                                                                 1-(3-thiacyclopentyl)-3-methyl-5-amino-                                                              yellow                            acid 2-isopropyl-5-methyl-phenyl ester                                                                pyrazole S-dioxide                                  20  4-amino-3-methyl-benzenesulphonic acid                                                                1,3-diethyl-5-amino-pyrazole                                                                         yellow                            x-nonyl-phenyl ester                                                       21  4-amino-3-trifluoromethyl-benzenesulph-                                                               1-ethyl-3-carboxymethyl-5-amino-pyrazole                                                             yellow                            onic acid 4-cyclohexyl-phenyl ester                                        22  4-amino-3-chloro-5-methyl-benzenesulph-                                                               1-iso-propyl-3-methyl-5-amino-pyrazole                                                               yellow                            onic acid 4-phenyl-phenyl ester                                            23  4-amino-3-carboxymethyl-benzenesulphonic                                                              1-hexyl-3-methyl-5-amino-pyrazole                                                                    yellow                            acid phenyl ester                                                          24  4-amino-3-acetylamino-benzenesulphonic                                                                1-(2-cyanoethyl)-3-methyl-5-amino-pyrazole                                                           yellow                            acid 3-methyl-phenyl ester                                                 25  4-amino-2,5-dichloro-benzenesulphonic                                                                 1-(2-trifluoromethyl-phenyl)-3-methyl-5-                                                             yellow                            acid butyl ester       amino-pyrazole                                      26  4-amino-3-trifluoromethyl-benzenesulph-                                                               1-[4-(N,N-bis-(2-hydroxy-ethyl)-sulph-                                                               yellow                            onic acid cyclohexyl ester                                                                            amoyl)-phenyl]-3-methyl-5-amino-pyrazole            27  4-amino-3-chloro-benzenesulphonic acid                                                                1-(2-hydroxyethyl)-3-phenyl-5-amino-                                                                 yellow                            octyl ester            pyrazole                                            28  4-amino-benzenesulphonic acid 3-methyl-                                                               1-phenyl-3-methyl-5-amino-pyrazole                                                                   yellow                            cyclohexyl ester                                                           29  4-amino-2,5-dichloro-benzenesulphonic                                                                 "                     yellow                            acid ethyl ester                                                           30  4-amino-2,5-dichloro-benzenesulphonic                                                                 "                     yellow                            acid phenyl ester                                                          __________________________________________________________________________ 

We claim:
 1. Disperse azo dyestuffs of the formula ##STR7## wherein R₁ " represents phenyl, tolyl, or chlorophenyl,R₂ " and R₃ " represent chlorine, R₄ " represents phenyl and R₅ " represents methyl.
 2. Azo dyestuff according to claim 1, of the formula ##STR8## 